1. Field of the Invention
The present invention relates generally to a method for keeping track of dates when a date field exceeds its predefined limit. More specifically the present invention relates to a method for reformatting a conventional 6, 7 or 8 digit date having fields displaying the day, month, and year to accommodate new century information and for incorporating such dates into existing systems.
2. Background and Description of the Prior Art
Digital date information in the 20th century has been commonly stored in a 6 digit format, in which 2 digits represent the month, 2 digits represent the day and 2 digits represent the year. It is argued that starting with the year 2000, 7 or 8 digits must be used for date entries so that centuries can be distinguished from one another. For example, conventional systems use three basic 6 digit formats each having a day field, a month field, and a year field. These are:
1. commercial, mm/dd/yy (most widely used in the U.S. business); PA1 2. government, yy/mm/dd (U.S. federal government standard); PA1 3. European, dd/mm/yy (common in Europe and Canada).
In each format, mm represents a month, dd represents a day, and yy represents a year. Problems arise in these conventional 6 digit systems when a new century approaches. For example, the first year of any century is represented in the commercial format as 01-01-00 through 12-31-00. Currently, there is no way to distinguish in this 6 digit format whether the date is Jan. 1, 1900 or Jan. 1, 2000. Thus, electronic databases that keep 6 digit date information for more than 100 years can quickly become confused as to exactly which date is meant by 01-01-00.
While some have suggested solutions to this problem, see e.g., Jerome Murray, The Year 2000 Computing Crises; a Millennium Date Conversion Plan, 1996, such plans have been complex and do not lend themselves to easy adaptation of current 6 digit database date formats.
Some have suggested that eight digits are required for date entry starting with the year 2000, while others have suggested that at least seven digits are necessary. However, reformatting the current databases from 6 to eight or seven digits can be costly and very time consuming. Moreover, a problem still arises in the seven digit format when a new millennium approaches. Furthermore, such a conversion and method of formatting dates uses additional computer memory. This may slow the computer down and more rapidly use up the memory available within the computer to the user.
What is needed is a simple method for manipulating and using a 6 digit date formats to accommodate century information that does not totally replace the 6 digit date format.